Thanks, Penguiniator (yes, you read my question perfectly), I wasn't sure when I posted the question that the problem had to do with more unresolved dependencies, since it didn't mention any such in the error message.
I managed to resolve them manually (learned a bit about urpmi in the process) and installed kpodder.
Forgive my recent Win32-user mentality, but it seems like an awful lot of software to install just for a simple podcast client: First it was looking for the X-devel includes, then the QT includes and binaries, then the KDE core/devel includes... All the same, good learning experience. Maybe I should have just gone with some command-line utility?
Speaking of urpmi, is this strictly a Mandriva utility? I intend to switch to another distro eventually (probably Debian), so am I correct in assuming urpmi is unknown to any non-Mandriva distro?
P.S: Anyone searching this forum for install questions for kpodder: Google up the packages that ./configure is reporting as missing, or try rpm.pbone.net and search for them there. Install the packages one by one if you have to, then ./configure will report the configuration is good and will ask you to proceed with the make.